1. Field
The present disclosure relates generally to antennas and, more particularly, to an antenna system utilizing a spherical lens and an antenna array to electronically scan the antenna system.
2. Related Art
The use of unmanned aerial vehicles (“UAVs”), commonly referred to as drones, has experienced explosive growth in this decade. Most UAVs utilize wireless technologies to control and communicate data between the UAV and a user terminal (“UT”). The control and data performance of this wireless link significantly limits the range, maneuverability and overall functionality of the UAV. As UAV use has expanded, the wireless link capabilities have become a limiting factor in the UAV system application space.
The UAV wireless link consists of radios and antennas at the user terminal and in the aircraft. The primary wireless “weak point” in the link is the UT antenna. The UT antenna's ability to efficiently track the aerial vehicle in flight is a significant coverage and range limitation. Attempts to address this issue have included the use of multiple terrestrial UT locations, satellites, and mechanically articulated antennas. The costs, complexity and logistics of multi-site terrestrial systems has limited their application. Satellite system complexity and data latency makes real-time control and observation of UAVs extremely complex and expensive. Mechanically articulated antennas have significant response time and pointing accuracy issues tracking the aerial vehicle. In the area of operations of the UAV it is desired to have a single UT system that can track the aerial vehicle efficiently at sufficient range to accomplish the operational objectives.
At present, one of the solutions to address the tracking latency issue is to utilize a phased array antenna which provides high antenna gain and electronically controlled steerability over the antenna field of view. Phased array antennas are complex to setup and operate, consume large amounts of power, and are expensive so their practical application is limited to high-end systems. Therefore, there is a need for a cost effective advanced antenna design that addresses the UAV tracking problem.